Section Authors:
Lisa Najavits (Chair, Division 50 EST Workgroup)
Nancy Piotrowski (Workgroup member), Greg Brigham (former Workgroup member)
Ashley Hampton (Workgroup student coordinator), Matthew Worley (former Workgroup student coordinator)


Substance use disorders (SUDs) are classified into two main categories: abuse and dependence, per the American Psychiatric Association Diagnostic and Statistical Manual, 4th edition, Text Revision (DSM-IV-TR; 2000). The DSM-IV-TR also identifies different classes of substances. These are alcohol; amphetamine; caffeine; cannabis; cocaine; hallucinogens; inhalants; nicotine; opioids; phencyclidine; and sedatives, hypnotics, or anxiolytics; and polysubstance (the latter referring to use of at least three classes of substances, but not including caffeine or nicotine, with no one substance predominating). The DSM-IV-TR also describes various important phenomena related to SUD diagnoses, including intoxication, withdrawal, tolerance, and remission. A current diagnosis refers to past-year timeframe; a lifetime diagnosis refers to having met criteria during some one-year period prior to the past year.

Criteria for SUD address various important impacts of substance use. Substance abuse criteria focus on substance-related problems at work or school; in dangerous situations, such as driving; with family and other important relationships; and with the legal system. Substance dependence criteria focus on tolerance, withdrawal; substance-related worsening of physical and/or mental health concerns; inability to control use of the substance; spending large amounts of time finding, using, and recovering from the substance; giving up other activities to use the substance; and continuing to use despite a strong desire to quit. See the DSM-IV-TR for more information.

Substance and Alcohol Disorders

Frequently Asked Questions